It is well established that modern humans originated in Africa, before moving out to inhabit rest of the planet. They first spread into Asia and Europe via the Arabian Peninsula, and those in the Far East eventually reached ...

A new analytical tool adds human factors to a widely-used biological model of how animal populations interact, suggesting that human societies can reach a steady state that is sustainable when they do not over-deplete natural ...

Empty nets and few species – environmental hormones are believed responsible for the diminishing numbers of fish. How damaging are these substances really, though? Studies that depict a complete picture of the lives of ...

The reintroduction of mountain lions across the mid-western United States has made species management an urgent area of research for conservationists. A report in the Wildlife Society Bulletin explores the fatal cost of human ...

An international team of scientists has used detailed analysis of ancient and modern DNA to show that the distribution and lack of genetic diversity among modern European beavers is due largely to human hunting.

Natural resource managers, policymakers and their advisers, and scientists have similar ideas about which research questions could, if answered, most increase the effectiveness of US natural resource management policies. ...

In Florida, where population growth, drought, and saltwater intrusion are affecting finite water sources, researchers are looking for effective ways to educate consumers about household water use habits. Despite an average ...

A substantial fraction of the Neanderthal genome persists in modern human populations. A new approach applied to analyzing whole-genome sequencing data from 665 people from Europe and East Asia shows that more than 20 percent ...

A new study on the human skeletal remains from the ancient Indus city of Harappa provides evidence that inter-personal violence and infectious diseases played a role in the demise of the Indus, or Harappan Civilization around ...

In the same way that fragments of ancient pottery and bones offer valuable information about human history, music can also reveal previously hidden clues about the past, according to new research from an international team ...

World population

The term world population commonly refers to the total number of living humans on Earth at a given time. As of 29 July 2009, the Earth's population is estimated by the United States Census Bureau to be 6.774 billion. The world population has been growing continuously since the end of the Black Death around 1400. There were also short term falls at other times due to plague, for example in the mid 17th century (see graph). The fastest rates of world population growth (above 1.8%) were seen briefly during the 1950s then for a longer period during the 1960s and 1970s (see graph). According to population projections, world population will continue to grow until around 2050. The 2008 rate of growth has almost halved since its peak of 2.2% per year, which was reached in 1963. World births have levelled off at about 134-million-per-year, since their peak at 163-million in the late 1990s, and are expected to remain constant. However, deaths are only around 57 million per year, and are expected to increase to 90 million by the year 2050. Since births outnumber deaths, the world's population is expected to reach about 9 billion by the year 2040.